This project involves the study of the effects of experimentally induced renal failure on the protein nutrition of rats. Rats are rendered acutely uremic by bilateral ureteral ligation or chronically uremic by subtotal nephrectomy or re-infusion of urine. Muscle protein and nucleic acid content are being measured as well as the effects of uremia on muscle protein synthesis in order to identify the cause of muscle protein wasting that occurs in renal failure. Supplements of specific amino acid analogues will be used to attempt to improve muscle protein nutrition. Thus, the effects of these supplements on muscle protein synthesis and degradation will be measured. In addition, the effects of different mixtures of amino acid analogues on waste product accumulation and excretion will be measured to design a more optional mixture that will minimize catabolism.